A review of hybrid biomanufacturing systems applied in tissue regeneration

Scaffold-based approach is a developed strategy in biomanufacturing, which is based on the use of temporary scaffold that performs as a house of implanted cells for their attachment, proliferation, and differentiation. This strategy strongly depends on both materials and manufacturing processes. However, single material is very difficult to meet all the requirements such as biocompatibility, biodegradability, mechanical strength, and promotion of cell adhesion. No single bioprinting technique currently can meet the requirements for all scales tissue regeneration. Thus, multi-material and mixing-material scaffolds have been greatly investigated. Challenges in terms of resolution, uniform cell distribution, and tissue formation are still severe in the field of bioprinting technique development. Hybrid bioprinting techniques have been developed to print scaffolds with improved properties in both mechanical and biological aspects for broad biomedical engineering applications. In this review, we introduce the basic multi-head bioprinters, semi-hybrid and fully hybrid biomanufacturing systems, highlighting the introduced modifications, improved properties, and the effect on the complex tissue regeneration applications.